Directory.Exists always returns false - Xtreme Visual Basic Talk

12-06-2006, 11:45 AM

wensly

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Join Date: May 2003

Location: London, UK

Posts: 36

Directory.Exists always returns false

Hi

I am trying to check whether a directory exists, by using the following code:

Code:

Dim bResult As Boolean = Directory.Exists("c:\temp")
MsgBox(bResult)

However, it always returns False even when the directory definitely does exist.

I've had a search around, and I'm thinking it may be something to do with security settings (although it doesn't throw any kind of exception).

Can anyone help please?

Thanks
Wendy

12-06-2006, 11:51 AM

reboot

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Works fine for me.

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12-06-2006, 12:16 PM

wensly

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Join Date: May 2003

Location: London, UK

Posts: 36

Hmm, definitely doesn't for me...

I've done some more investigation, and it seems that Directory.Exists may not actually be looking at my c drive at all. If I get a file listing as follows:

Code:

Dim str As String
Dim FileList() As String
 
FileList = Directory.GetFiles("c:", "*")
For i As Integer = 0 To FileList.Length - 1
  str &= FileList(i) & Chr(13)
Next i

MsgBox(str)

...the msgbox returns:
MyProject.exe
MyProject.exe.config
MyProject.pdbc

So, it's doesn't actually seem to be looking at my c: drive at all, but at the project directory.... Directory.Exists("c:") also returns True.

If I use the same code as above, but get it to search in "c:\" (i.e. with a backslash), it raises a security exception:

An unhandled exception of type 'System.Security.SecurityException' occurred in mscorlib.dll

"Additional information: Request for the permission of type System.Security.Permissions.FileIOPermission, mscorlib, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b77a5c561934e089 failed."

Any ideas?

Thanks
Wendy

12-07-2006, 06:59 AM

wensly

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Join Date: May 2003

Location: London, UK

Posts: 36

I got some help on this from a colleague, so thought I would post the solution we found. The problem *was* to do with my security settings, and the following steps fixed it:

1. Go to Control Panel | Administrative Tools | Microsoft .NET Framework 1.1 Wizards
2. Click 'Trust an Assembly'
3. Next
4. Add the exe file as a 'manged assembly to trust'
4. Next
5. Selected 'Full Trust'

Directory.Exists then returns the correct result

The only problem with the above is that the exe needs to be re-trusted each time it's compiled, so if anyone has any ideas about how to always trust projects that I create, I'd be interested to hear them.

Thanks
Wendy

Last edited by wensly; 12-07-2006 at 07:05 AM.

12-07-2006, 07:33 AM

wayneph

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Are you creating it on your C:\ drive or is it running from a network location or something like that? I've never had a problem with locally created apps. On the Network, I have set up a Trusted location so that I can create apps in a location that is backed up, and don't run into the Security Exceptions.

Any more information you can provide about your development environment would be appreciated.

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12-07-2006, 07:41 AM

wensly

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Join Date: May 2003

Location: London, UK

Posts: 36

Hi, thanks for your reply.

It's on my local drive in a directory called c:\Projects\MyProjectName, and it gets checked into Source Safe at the end of every day. I know that if I try to save a project to a network location, it tells me that it's not trusted, but this does not happen when I save to c:\Projects.

To be honest, I don't have a clue about permissions / security, so I'm not sure what other options / settings I might need to look at...